LGF, I believe it is state that over rides the federal, but only if the state rules are tougher. As with most things, MA is tougher than the federal laws.

I will check this out to make sure, but at my "other" job we have run into this because we have offices in more than one state and have had to amend company policy on things when we have opened other offices or bought out other companies.

For instance, we purchased a company in CA. We had to change a bunch of payroll and benefit policies of our office in MA because the CA state laws were tougher. Of course we didn't have to, but in order to keep the entire company with the same policies we had to adopt some from another state. And of course the federal laws were much more lenient.

But again, I want to double check to make sure I have not completely messed up my point....

I thought federal superseded state?
Yes, Federal law must be followed by all states. but a state may add onto federal law making it stronger.

The same thing down the chain. Federal, state, county, city/town.

Example (not reality but eventually may be ): County law states you cannot smoke unless there is a separate enclosed smoking section. The state makes a law stating you cannot smoke in any restaurant or bar. The county must adapt it's self to follow that law.
The county could add on to the law making it illegal to smoke in all county parks. Then the town can come in & bans smoking anywhere in the entire town.

All tho it would be legal in the state to smoke, it would still be illegal in the town & you would be paying that damn fine.

Thank god that day isnt here....

A law may have an opt in clause, such as the neighborhood nodification law for pesticides in the state. Or various other laws that usually come with extra $ for the countys that opt in. or can take away funding for ones that dont. Such as the federal speed or dwi limit. If a state chooses not to opt in they loose major federal funding so most places choose to opt in even tho some specific lawd may not be "required" to follow.